CAMP FOSTER, Okinawa — Residents of a town near Kadena Air Base are being told to stay away from untreated spring water after high levels of a banned pollutant were detected last year.

High concentrations of perfluorooctanesulfonic acid, or PFOS, and perfluorooctanoic acid, or PFOA, were found during two underground-water surveys in June and July, according to an assessment released April 26 by the Okinawa Prefectural Enterprise Bureau, administrators of the island’s water supply and quality.

“We talked to the neighborhood assemblies to tell their district people not to drink the water in these areas,” a Kadena town spokesman told Stars and Stripes Tuesday. “In these spots, there are animals, like small fish, and local kids play in the water. We have asked the prefectural government to do further research to determine where these chemicals are coming from as well as study the effect on crops as there is a farming area nearby.”

The spokesman discussed matters related to pollution on the Japanese customary condition of anonymity.

PFOS and PFOA are synthetic, fully fluorinated organic acids, which are virtually the same, though their concentrations differ depending on the product, Okinawan officials previously told Stars and Stripes. They are found in firefighting foam, aircraft grease, water-repellant materials and fluorine chemicals. They have been known to cause tumors, increases in body and organ weight and death in animals.

U.S. military officials in Japan say the source of the PFOS and PFOA pollution on Okinawa is not necessarily U.S. military facilities. They have also begun phasing out old aircraft firefighting foam with one featuring a new formulation.

Expanded testing

Japan has no guidelines on how much of the acids are safe, but health advisories in the United States are issued for drinking water at levels of 0.07 micrograms per liter and above. Their manufacture and importation have been prohibited in Japan since 2010.

Enterprise bureau officials on Okinawa periodically test for the pollutants at two sites not far from Kadena Air Base. Both are intake pumps for the Hija and Nagata rivers and are approximately a half-mile from the fence line, officials said.

However, in summer 2018, they expanded their testing to 19 sites surrounding the intake pumps because of past high levels. Some of the sites are about a half-mile from the fence line while others are closer.

Of the 19 spots tested, 13 exceeded safe U.S. drinking water standards, the enterprise bureau report states. Five sites exceeded the capacity of the bureau’s testing equipment, which was designed to accurately test up to 1 microgram per liter for PFOS or PFOA.

On June 26, Yara Shiriga’s PFOS level was 1.766 micrograms, Yara Ubuga was 2.821 and the lower Hija River pump intake area was 2.145. All of these sites are in Kadena town.

A month later they were 1.673, 3.128 and 1.337, respectively.

High levels of PFOS were also detected at Yara Hijaga, which was 3.085 on June 11 and 2.901 on June 26.

Prefectural officials have been reporting high levels of these pollutant compounds around U.S. military bases on the island for years. In response to these most recent tests, signs were posted to ensure locals stay away.

Drinking water on and off base is considered safe, a bureau spokesman added. The water on and off base — supplied to Kadena and the surrounding area by the Chatan Water Treatment Plant — averages 0.029 micrograms of PFOS and PFOA collectively per liter after being treated, though it has been clocked as high as 0.063.

The plant also provides water to Okinawa City, Ginowan, Urasoe, Naha, Chatan, Kitanakagusuku and Nakagusuku.

The 2018 average for water treatment plants in Ishikawa, Nago and Nishihara were all less than 0.01 micrograms per liter. These treatment plants are in southern, central and northern Okinawa and are not near any military air bases.

Placing blame

Okinawan officials said they believe the pollution is coming from Kadena Air Base; however, they cannot be sure because they don’t have base access.

“It is pretty certain that Kadena Air Base is causing the high PFOS by using firefighting foam containing PFOS at the flight line; however, we haven’t been able to investigate on their side to make a definitive determination,” the enterprise bureau spokesman said. We “asked Okinawa Defense Bureau to demand Kadena stop using the firefighting foam containing PFOS and disclose the record of usage in January 2016.”

Bureau officials said they were told in February 2016 the foam would be replaced with one not containing the pollutants.

There have been similar issues reported at nearby Marine Corps Air Station Futenma. Seven sites exceeded healthy U.S. drinking water standards in prefectural testing over the winter, an Okinawa Prefectural Government spokesman said Tuesday.

“High PFOS levels keep being detected in wells below the Futenma flight line,” the spokesman said. “We can’t go onto the base to test or investigate but the probability is pretty high that it comes from [aircraft] firefighting foam. We have asked Futenma to give us details on usage of the [foam] but we haven’t had any luck.”

During a lengthy interview with USFJ officials on the topic between January and March, spokesman Marine Capt. Michael Hopkins said the pollution could have come from a variety of sources.

He also said Japanese government officials have been allowed to investigate on Kadena Air Base per established bilateral agreements, and that they agree with this assessment.

“It would be inappropriate to speculate where the presence of PFOS and PFOA in off base waterways originated,” Hopkins wrote to Stars and Stripes in January.

“The U.S. works diligently to comply with the Japan Environmental Governing Standards and Department of Defense instructions. The U.S. is and will continue to work with the Government of Japan in a methodical and tiered approach on the issue.”

Foam phase-out

Kadena currently has the compounds in one active foam fire-suppression system, scheduled to be replaced in the near future, and two deactivated systems, which cannot be used, Hopkins said in March.

“Industry standard practice is for the [foam] concentrate to remain in the fire suppression system for extended periods,” he said. “The Government of Japan recognizes the continued use of firefighting foam containing PFOS, as change out takes time.”

The air base is transitioning to an aircraft firefighting foam that is PFOS free and contains only trace amounts of PFOA, Hopkins said. Foam containing the pollutants has already been “swapped out” of the air base’s emergency vehicles.

The Marine Corps will be phasing out the foam over the next “several years,” Hopkins said. Starting in March 2016, water has been used in all firefighting training at Futenma.